Subroutines

1)Subroutines

• Program module that can be called by any program.

• You use subroutines to avoid having to write frequently

used program components more than once. Data can be

passed explicitly from and to subroutines.

• Types of subroutine

– internal subroutines

– external subroutines

2)Defining and calling subroutine

Definition - Syntax

FORM .

.

ENDFORM.

Calling - syntax

a)Internal Subroutines

PERFORM .

b)External Subroutines

PERFORM () [IF FOUND].

- Program name

IF FOUND - If this is specified and there is no

subroutine _{in the program ,}

the system ignores the PERFORM statement.

Examples of subroutines